My buddy had the same problem with his new to him TT. It's the air in-take valve next to the fill that is probably clogged and not allowing a pure flow of water. Just like opening the small air portal on the back of a gas can for example...allows for smooth pouring of gas. That was his problem we found out...anyway...hope this helps some.
2007 Jay Series 806
2012 Jay Feather Ultra Lite X20E